Question

Jane has 60 liters of 70% of acid solution. How many liters of water must be added to form a solution that is 40% acid?

Answer 1

Let w = liters of water needed
4.70= acid in 40% solution 

4.70/70+w  = .28

28=.28.(70+w)
70+w=100
w=30


30 liters of water is needed